10-bit. (Not a firmware update thread, I promise)

[GrandLunar]

Hey all,

Not to sound like a newb but: I'm just trying to wrap my head around how an external recorder works.

The AF100 is a 8-bit camera (right?) but when you use an external recorder, does it somehow magically get bumped up to 10-bit? Or is it saying that the recorder can save UP to 10-bit.
I know it basically records uncompressed footage.. so does the 4/3 sensor already have 4:2:2, it just needs a recorder for the information or...


(I tried looking for a thread like this, but if there is one I'd love to be re-directed to it)

Any insights would be greatly appreciated.

 

[Barry_Green]

No. There is no practical benefit to using a 10-bit recorder. And really, the whole 10-bit thing is kind of overblown because there's only really one camera on the market under $14,000 that does 10-bit clean enough to actually get the full benefit of 10 bits, and that's the F3. Anything else either outputs only 8 bits, or is a little bit noisier than 10-bit really needs.

The SDI and HDMI outputs on the AF100 do output a full 4:2:2.

 

[marlontorres]

So is considering an external recorder for the AF100 pointless?

 

[Barry_Green]

No, but worrying about 10-bit is. And I think a lot of people who were thinking that they would "need" an external recorder, are going to be very pleasantly surprised that they in fact don't. I say try the native codec before you worry about external recording.

External recorders have several advantages. Not the least of which is, redundancy. If you are shooting in a scenario where you absolutely must have two copies of the footage, an external is the way to get it. Also, most external recorders can deliver 4:2:2 color sampling, which is a bonus especially for greenscreening. And the external recorder provides resistance from codec overload -- meaning, if you get into a situation where the native codec gets overloaded and you start seeing compression artifacts, the external recorder can be a more robust codec that resists overload (assuming you have a high-enough-quality external, such as a ProRes recorder or a Nano running at 200+mbps).

And, an external recorder may possibly make your footage more edit-friendly, if you're a Mac user. External recorders frequently record in Quicktime .MOV format. Mac NLEs just don't bother with importing native camcorder footage, they pretty much demand that you transcode everything with Log & Transfer. With Windows, you can pretty much drag 'n' drop the footage from any camcorder into any editor. The external recorder can make it so that a Mac user gets that same kind of flexibility.

On the downside, external recorders cost money to buy, they have to be powered separately, they involve strapping more gear on your rig, and the footage takes up massively more space. A ProRes recorder will take up about 10x as much space as the AF100's native codec. That means that a 16GB card in the camera, would require 160GB of storage space in an external recorder.

So, the question is -- do you NEED an external recorder? I know there's a lot of excitement about them because everyone and their brother has released one and there are many on the market, but ... if the internal codec does what you need, why spend $1000 to $6000 on an external?

So only you can decide whether your workflow would benefit from using an external recorder. Some folks will. And a lot of folks will get caught up in the buzz and hype and end up spending a thousand dollars or more on something that won't do much of anything to really improve their footage.

For some cameras it makes more sense than for others. For an F3, I consider an external recorder mandatory to actually extract what that camera can do. Its onboard codec is nowhere near adequate to handling what the camera can deliver; Sony themselves say it should be used for "proxies". The F3 is capable of 4:2:2 10-bit output, and the only way to take advantage of that is with an external. And the price of the external is pretty reasonable, in comparison to the overall system cost of an F3. $13,300 for the body, and $2500 for a PIX 240, is a good combo. You get a substantial boost in image quality for a system cost of maybe 10% for a Samurai, for example.

But on the AF100, you're talking about a $4700 body. Is it really worth $2500 for an external recorder, just to get 4:2:2? I think most of us would be plenty satisfied with the onboard codec, as it's a pretty good match to the system and performs quite well, and it's cost-efficient. (and no, I don't consider a Ninja at $1000 to be a good match, because it's HDMI-only and doesn't take advantage of 24PsF, etc; just like I wouldn't recommend the PIX 220 for the AF100 either, I'd say get a Samurai or a PIX 240 or a Nano or something like that). But even so, you're talking about spending 30% to 50% of the system cost on a recorder, and getting only (really) 4:2:2 as a benefit. Sure, 4:2:2 is nice, but is it worth it when viewed as an entire system? I don't think it makes a lot of sense for most folks, but for those who it does make sense for, there are indeed gains to be had.

In general, I think there are a lot of ways that money can be spent that will have a more significant impact on your footage, than on an external recorder. Lights, a great mic, an external sound mixer, gels, grip stuff, all that stuff. If you already have all that, and are looking for the next level up, then yeah, an external recorder might be what to look for. But only after you've got everything else in place, or if you have a specific need for what an external recorder gives you.

 

[Barry_Green]

OF course, another reason for an external recorder is if you're shooting a show for the BBC; the BBC has approved the AF101 for acquisition when it's used with an external recorder at >50mbps. So if that's what your client or network demands, then an external recorder can deliver it.